Oilpan: fix build after r170943

Source/core/animation/StringKeyframe.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/animation/StringKeyframe.h"
 
 #include "core/animation/Interpolation.h"
 #include "core/animation/css/CSSAnimations.h"
 #include "core/css/resolver/StyleResolver.h"
@@ skipping 31 matching lines @@
 {
     return adoptRefWillBeNoop(new StringKeyframe(*this));
 }
 PassOwnPtrWillBeRawPtr<Keyframe::PropertySpecificKeyframe> StringKeyframe::createPropertySpecificKeyframe(CSSPropertyID property) const
 {
     return adoptPtrWillBeNoop(new PropertySpecificKeyframe(offset(), easing(), propertyValue(property), composite()));
 }
 
 void StringKeyframe::trace(Visitor* visitor)
 {
+    visitor->trace(m_propertySet);
     Keyframe::trace(visitor);
 }
 
 StringKeyframe::PropertySpecificKeyframe::PropertySpecificKeyframe(double offset, PassRefPtr<TimingFunction> easing, CSSValue* value, AnimationEffect::CompositeOperation op)
     : Keyframe::PropertySpecificKeyframe(offset, easing, op)
     , m_value(value)
 { }
 
 StringKeyframe::PropertySpecificKeyframe::PropertySpecificKeyframe(double offset, PassRefPtr<TimingFunction> easing, CSSValue* value)
     : Keyframe::PropertySpecificKeyframe(offset, easing, AnimationEffect::CompositeReplace)
@@ skipping 24 matching lines @@
     Keyframe::PropertySpecificKeyframe *theClone = new PropertySpecificKeyframe(offset, m_easing, m_value.get());
     return adoptPtrWillBeNoop(theClone);
 }
 
 void StringKeyframe::PropertySpecificKeyframe::trace(Visitor* visitor)
 {
     visitor->trace(m_value);
 }
 
 }